Metering valve for pressurized vial

ABSTRACT

A metering chamber ( 7 ) is fixed by its upper end to the portion of a valve body ( 9 ) located, in the mounted state, inside the vial, an inlet passage being provided contacting the inside of the vial and the metering chamber and an outlet passage contacting the metering chamber and the outside of the valve. The inlet passage can be closed when the valve element ( 4 ) is in the open position and the outlet passage can be closed when the valve element ( 4 ) is in the closed position. In addition, the valve element can be moved beyond the open position into a third position, called short-circuit position, a third passage, called short-circuit passage, being provided to contact the inside of the vial and the outside of the valve. The short-circuit passage can be closed when the valve element ( 4 ) is in the closed position or the open position.

The invention relates to a metering valve for pressurized vial, comprising a valve body in which a valve element can slide, a metering chamber and means for moving the valve element between a closed position in which, in the mounted state on a vial, the metering chamber is in contact with the inside of the vial and isolated from the outside of the vial, and an open position in which, in the mounted state, the metering chamber is isolated from the inside of the vial and in contact with the outside of the vial.

The metering valve of the invention is intended for a pressurized vial. Metering devices for valves of pressurized vials are commonly used to deliver a predetermined amount of a product. The product to be dispensed is in a vial containing a propellant gas. The product is either in direct contact with the propellant gas or contained in a flexible pouch immersed in the propellant gas.

Various types of metering devices for valves of pressurized vials are known.

For example, document EP 1 099 647 A1 proposes a metering device equipped with a metering chamber located downstream of the valve, placed on the rod (stem) of the valve of the vial. The metering chamber is constituted by a cylinder in which a piston slides. The bottom of the cylinder is provided with an orifice which is in direct contact with the outlet of the valve stem. The piston is also provided with an orifice which is continued by an axial tube which slides in a security element in which there is a second valve. To withdraw a dose of product, it is necessary initially to move the cylinder of the metering chamber down so that it bears on the valve stem and thus opens the latter. The pressurized product coming out of the valve of the vial enters into the metering chamber by pushing the plunger upwards. The product also penetrates into the tube leading to the outlet valve of the security element. Once the metering chamber is full, the cylinder is returned to the rest position to close the valve of the vial. It is now possible to operate the valve of the safety element by pushing on a traditional diffuser. To move the cylinder down in order to fill the metering chamber, it is necessary to rotate a ring in which are formed two slanted guide grooves and in which two peripheral projections of the cylinder penetrate. Thus, when the projections are in the upper portion of the grooves of the ring, the cylinder is in the high position and is not bearing on the valve stem of the container. On the contrary, when they are in the lower portion, the cylinder is translated downwardly and it bears on the rod so as to cause the valve of the vial to open. Therefore, to withdraw a dose, it is necessary, firstly, to turn the ring a first time to fill the metering chamber, then a second time to close the valve of the vial. It is then necessary to press on a diffuser located in the top portion of the security element to open the second valve. This device is not very easy to use. In addition, it requires two different valves.

Document EP 0 642 992 A1 discloses a metering device intended to be mounted in the opening of the neck of a container containing the product to be dispensed. The metering device is equipped with a valve comprising a metering chamber and a stem. In a first position of the stem, the metering chamber is in contact with the inside of the container and fills up with a given quantity of the product. In a second position of the stem, the metering chamber is isolated from the inside of the container and is contacted with the outside, allowing the product contained within to be expelled. For this purpose, the metering chamber is axially delimited on one side by an annular valve seal and on the other side by a chamber seal which is also annular. The stem passes through both seals. It comprises a first distribution channel arranged axially and open downwardly and upwardly by two radial openings. It comprises a second distribution channel arranged axially, which has, on the side oriented toward the first channel, a radial opening, and on the side of the free end of the stem, an axial opening. In the rest position, maintained by a spring, the stem is positioned so that the upper opening of the first channel is located within the metering chamber between the two seals while the radial opening of the second channel is closed by the valve seal. The lower opening of the first channel opens inside the vial. In this position, the metering chamber fills up with the product contained in the container via the first channel as soon as the vial is turned upside down. If the user presses on the stem against the force of the spring, the radial openings are displaced. The upper opening of the first channel is closed by the chamber seal while the radial opening of the second channel opens into the metering chamber. The product, mixed with the propellant gas, is expelled from the metering chamber under the effect of the pressure via the second channel. This device requires that the vial be upside down in order to be used.

Document DE 79 14 704 U1 discloses a metering device in which the metering chamber is formed by a recess closed by an elastic wall. Depending on the model, the recess has a hemispherical or diabolo shape. The elastic wall bathes is subjected to the pressure in the pressurized vial. As soon as the metering chamber is placed in contact with the outside, the elastic wall is pushed back inside the recess so as to trigger the expulsion of its contents.

Document FR 1 503 684 A discloses a metering device intended to be mounted on the valve body, within the vial. The device is provided with a metering chamber which opens into the valve body. In order to manufacture the vial ready-to-use, it is necessary to fill the container with the desired liquid, crimp the valve, then introduce the gas via the outlet passage. An opening is provided in the tube connecting the metering chamber to the valve body. This opening is surrounded by an elastic sleeve which expands under the effect of pressure and thus allows gas to escape inside the container.

None of the vials presented makes it possible to introduce the product into the vial via the valve, as is commonly the case with vials provided with a simple valve. Similarly, none of these vials allows withdrawing an amount greater than that delivered by the metering chamber, except by operating the valve several times in a row. The goal of the invention is to develop a metering device for a valve of a pressurized vial which, although provided with a metering chamber, can be filled via the valve. Another objective of the invention is to be able to not only withdraw a dose defined by the metering chamber but also a dose different from the one imposed by the metering chamber without the need to operate the valve several times. A third objective is to make it possible to use the same valve for vials with head-up withdrawal and vials with head-down withdrawal.

This objective is achieved according to the invention in that, on the one hand, the metering chamber is fixed by its upper end to the portion of the valve body located, in the mounted state, inside the vial, an inlet passage being provided contacting the inside of the vial and the metering chamber and an outlet passage contacting the metering chamber and the outside of the valve, inlet closure means being provided to close the inlet passage when the valve element is in the open position and outlet closure means being provided to close the outlet passage when the valve element is in the closed position. Moreover, the valve can be moved beyond the open position into a third position called short-circuit position, a third passage, called short-circuit passage, being provided for contacting the inside of the vial and the outside of the valve, short-circuit closing means being provided to close the short-circuit passage when the valve element is in the closed position or in the open position. In the short-circuit position, it is possible to withdraw a quantity of product greater than that imposed by the volume of the metering chamber. Similarly, it is possible to fill the vial via this short-circuit passage.

It is preferable that the inlet closure means and/or outlet closure means are in the closed position when the valve element is in the short-circuit position if the short-circuit passage does not pass through at least a portion of the inlet passage and/or the outlet passage. Similarly, it is preferable that the short-circuit passage contacts the inside of the vial and the outside the valve without passing through the metering chamber.

It is preferable that the inlet closure means and the outlet closure means are independent from one another.

In a preferred embodiment of the invention, the inlet passage is constituted by at least one hole made in the wall of the valve body, in a zone in contact with the inside of the vial or pouch, an orifice made in a wall located within the valve body and an orifice made in the wall of the metering chamber, and in that the inlet closure means are constituted by the lower end of the valve element having the shape a cylindrical tenon and whose radial cross-section corresponds to the inner dimensions of the orifice of the wall so that when the tenon enters the orifice, it closes it sealingly, the wall having preferably the shape of a collar ending in the shape of a funnel oriented toward the metering chamber. To enhance the sealing of the inlet closure means, it is preferable to place sealing means, preferably an annular ring, below the orifice made in the wall. Thus, when the tenon comes into contact with the orifice in the wall of the valve body, it also comes to bear against the annular ring.

The outlet passage is preferably constituted by an orifice made in a wall of the metering chamber, an orifice made in a wall located within the valve body, a lower central channel and an upper central channel made in the valve element and separated from each other by a barrier, at least one orifice being made in the wall of the valve element and contacting the inside of the upper central channel and the outside of the valve element and at least one orifice being made in the wall of the valve element and contacting the inside of the lower central channel and the outside of the valve element, a contacting passage being provided for contacting the orifice or orifices with the orifice or orifices, and in that the outlet closure means are constituted by a chamber seal constituted by an annular wall within which the valve element is slidable, the inner face of the chamber seal having at least one annular groove whose height is at least equal to the vertical distance separating the orifice or orifices made in the upper central channel and the orifice or orifices made in the lower central channel, the orifice or orifices of the upper central channel and/or the orifice or orifices of the lower central channel being closed by the inner face of the annular wall when the valve is in the closed position, thereby closing the outlet passage, and the orifice or orifices of the upper central channel and the orifice or orifices of the lower central channel opening into the annular groove when the valve is in the open position, thus freeing the outlet passage.

It is preferable that the metering chamber comprises a cylinder whose end opposite to the valve body, called lower end, is closed by a radial wall, called lower radial wall, and whose end oriented toward the valve body, called upper end, is closed by a radial wall, called upper radial wall, a piston being slidable within the cylinder between these two radial walls so as to define a metering volume.

In this case, the upper radial wall of the metering chamber can be provided with an opening, the piston being slidable between the two radial walls of the cylinder, a spring being provided between the lower radial wall of the metering chamber and the piston to return the latter, in the absence of other constraints, against the upper radial wall provided with the opening.

In order to enable the introduction of the piston into the metering chamber, it is preferable that the cylinder forming the metering chamber, on the one hand, and its radial wall upper and/or its lower radial wall, on the other hand, constitute different parts that can be assembled or separated from one another, means being provided for fixing said wall on the cylinder.

In order to separate the propellant gas and the product, it is possible to weld a flexible pouch on the valve body enclosing the metering chamber and the beginning of the inlet, outlet and possibly short-circuit paths. Thus, when a pouch is provided, the inlet, outlet and possibly short-circuit paths open upstream, not into the vial, but into the pouch. With such a pouch, the valve can be used regardless of the position of the vial.

In practice, the valve element can be constituted by a first cylindrical wall, called upper cylindrical wall, forming a first axial channel, called upper channel, and a second cylindrical wall forming a second axial channel, the two axial channels being isolated from each other by a barrier, the upper channel being open at its upper end by an axial opening and on the side of the barrier by at least one radial opening that opens onto the outer face of the valve element, the lower channel being open at its lower end by an axial opening and on the side of the barrier by at least one radial opening that opens onto the outer face of the valve element, the valve element being preferably provided with at least one annular stop on its circumference in order to limit its movement within the body valve toward the outside or the inside.

Correspondingly, the valve body can be provided with a chamber seal disposed within the valve body so that, in the closed position of the valve, the radial hole or holes of the upper channel of the valve element are located in the vicinity of the chamber seal and closed by the latter, the annular stop coming to bear sealingly against this chamber seal.

When the valve must be able to short-circuit the metering chamber, it is preferable to provide the valve element with a third cylindrical wall at least partially surrounding the first cylindrical wall and concentric thereto so as to form an annular channel, which annular channel is isolated from the other two and provided with an axial opening at its so-called upper end and at least one radial hole contacting the inside of the annular channel and the outside of the valve element. In this case, the valve body and the valve element are dimensioned so that the valve element can be moved beyond the open position into a position called short-circuit position, and the valve body is provided with a valve seal disposed opposite to the metering chamber relative to the chamber seal and positioned so that, in the mounted state of the valve, the radial hole or holes of the annular channel are, in the closed position of the valve, outside of the vial, in the open position of the valve, the radial hole or holes of the annular channel are located facing the valve seal and closed by the latter, or outside of the vial, and in the short-circuit position of the valve, the radial hole or holes of the annular channel are located on the side of the valve seal opposite the outside.

At least one side channel can be provided on the outer face of the valve body, said side channel being provided with a first opening that opens, in the assembled state, inside the vial or the pouch, and a second opening that opens inside the valve body between the valve seal and the chamber seal. When the valve is provided with a flexible pouch, the latter is welded to the valve body so as to enclose the first opening of the side channel or channels of the valve body so that the side channel or channels contact the inside of the pouch and the inside of the valve body between the valve seal and the chamber seal.

The invention is described in more detail below using an exemplary embodiment shown in the following figures, which show:

FIG. 1: a cross-sectional side view of the metering valve as a whole;

FIG. 2: an exploded view of the metering valve;

FIG. 3: an enlarged cross-sectional (a) front view and (b) side view of the valve in the closed position;

FIG. 4: an enlarged cross-sectional (a) front view and (b) side view of the valve in the open position;

FIG. 5: an enlarged cross-sectional (a) front view and (b) side view of the valve position in the short-circuit position;

FIG. 6: the spacer (a) in perspective view and (b) in cross-sectional view;

FIG. 7: The chamber seal (a) in perspective view and (b) in cross-sectional view;

FIG. 8: the cover of the metering chamber (a) in perspective view from above and (b) in perspective view from below;

FIG. 9: the bottom of the metering chamber (a) in perspective view from above and (b) in perspective view from below;

FIG. 10: the valve body (a) in perspective view from above, (b) in perspective view from below, (c) in cross-sectional front view, (d) in cross-sectional side view and (e) in perspective view looking down;

FIG. 11: the stem (a) in cross-sectional front view, (b) in cross-sectional side view, and (c) in perspective view;

FIG. 12: the piston (a) in perspective view from above, (b) in perspective view from below, and (c) in cross-sectional view.

For clarity of description, spatial references are used such as “lower” and “upper” or “inside the vial” and “outside the vial.” It should be noted that the valve is manufactured and sold independently of the vial and the protection shall include in particular the valve alone without vial. Accordingly, these references are made relative to the valve as it is intended to be used assembled onto a vial whose valve is located above the vial. This does not prevent the valve from being used in an inverted position, that is to say, with the valve below the container, or in any other position.

The valve (1) is intended to be fixed to a rigid vial, not shown, by means of fastening means such as a cup (2). A seal called outer seal (21) is provided between the vial neck and the cup (2) to ensure sealing. Conventionally, the valve (1) is fixed to the dome (22) of the cup (2).

The valve (1) is essentially constituted by

-   -   a valve body (9) attached to the dome (22) of the cup (2);     -   a valve element, usually called stem (4), located in the valve         body (9) in which it can move axially between a closed position         and at least a first open position;     -   a spacer (3);     -   two inner seals (5 a, 5 b);     -   a metering chamber (7).

The valve generally comprises an inner pouch (11) allowing the separation of the product from the propellant gas.

The valve body (9) is constituted by of an upper portion (91) having the shape of a cylindrical ring which is intended to be fixed in the dome (22) of the cup (2). An inner valve seal (5 a) is arranged between the front face of this upper portion (91) and the bottom of the dome (22) in order to ensure sealing. This sealing is improved thanks to the tapered shape of the front face of this upper portion (91).

This upper ring (91) of the valve body (9) is extended by a substantially cylindrical main portion (92).

An axial channel (95) passes through the main portion (92). This channel is divided into an upper section and a lower section separated by a radial collar (98) oriented inwardly and provided with a central orifice. The upper section is provided with two sets of radial ribs oriented toward the center of the axial channel (95). The first set of radial ribs (96) forms, on the one hand, in its upper part, a stop for a second inner seal, called chamber seal (5 b) and described below, and on the other hand, a sliding guide for the stem (4). The second set of radial ribs (97) additionally forms a stop for a shoulder of the stem (4). The first set of ribs (96) is located above the second set (97).

The product can circulate between the ribs. The free ends of the ribs of the first set (96), which are oriented toward the center, are located farther from the central axis of the valve body than the free ends of the ribs of the second set (97).

Two radial orifices (99) are formed in the wall of the main element (92), above the collar (98) located within the valve body. This collar (98) is extended by a funnel-shaped portion (981) that tapers downwardly.

The outer face of the valve body (9) has two radial fins (93). These fins have, in the radial plane of the valve body, a V-shaped cross-section, the wings of the V bearing more or less tangentially on the cylindrical portion of the main element (92). These two fins (93) are disposed opposite to one another and are hollow. There is thus formed within each fin (93) a side channel (931) which is open at its lower part (the side opposite to the upper ring) and closed at the top. Each channel (931) is provided in its upper part with an orifice (94) that opens into the upper section of the axial channel (95) slightly below the upper ring (91), but above the seat for the internal chamber seal (5 b). The orifices (94) contact each channel (931) located within the fins and the space located within the upper ring (91).

The flexible pouch (11) is fixed, for example by welding, on the outer face of the main portion (92). The pouch (11) is closed on all sides and can communicate with the outside only through the valve. With this pouch, it is possible to separate the product to be diffused from the propellant gas located outside the pouch. However, it would be absolutely possible to proceed without the pouch.

The stem (4) has a substantially cylindrical outer shape and includes a first cylindrical wall (41) forming an upper central channel (42) which is open at its upper end by an axial opening and a second cylindrical wall (44), forming a lower central channel (442) which is open at its lower end by an axial opening. The two central channels (42, 442) are isolated from each other by a barrier (43). The second cylindrical wall forms a cylindrical tenon (44). The upper part of the outer face of the tenon, that is to say on the side of the barrier (43), has a circular shoulder (441). The inside diameter of the narrow portion of the funnel (981) corresponds to the outer diameter of the tenon (44) of the stem (4).

A first set of two radial holes (45) is formed in the first wall (41) of the stem (4), near the lower end of the central channel (42). Thus, these first radial holes (45) contact the inside of the central channel (42) and the outer face of the stem (4). Similarly, the second cylindrical wall forming the tenon (44) is open in its upper part, in the vicinity of the barrier (43), by a second set of two radial holes (443). These two radial holes open above the shoulder (441)

The stem (4) is further provided with a third cylindrical wall (46) concentric with the first (41) and surrounding it so as to form an annular channel (47) concentric to the upper central channel (42). This annular channel (47) is open at its upper end by an axial orifice and closed toward the bottom. Its length is such that the first radial holes (45) do not pass through it. A third set of two radial holes (48) passes through the third cylindrical wall (46) so as to contact the inside of the annular channel (47) and the outside of the stem (4). The holes (48) of this third set open above the holes (45, 443) of the first and second set.

The stem (4) is additionally provided with two circular stops (49 a, 49 b) located on its periphery. The outer diameter of the first stop (49 a) corresponds substantially to the diameter of the cylinder formed by the inner ends of the first portion of the ribs (96) of the axial channel (95) of the valve body (9). The outer diameter of the second stop (49 b) corresponds substantially to the inner diameter of the spacer (3). The first stop (49 a) is located below the second (49 b).

In the assembled state, the stem is located in the valve body within the axial channel (95) in which it can move. The movement of the stem is limited between two extreme positions, the upper or closure position and the lower or short-circuit position. Downwardly, that is to say in the short-circuit position, the movement is limited by the first stop (49 a) which comes to bear on the upper portion of the second set of ribs (97) whereas upwardly, that is to say in the closure position, the movement is limited by the second stop (49 b) which comes to bear against the inner valve seal (5 a) located in the dome (22) of the cup (2). In this position, the movement is also limited by the first stop (49 a) which comes to bear on the inner chamber seal (5 b).

The spacer (3) is formed by a hollow cylinder provided in its upper portion with radial ribs (31) oriented outwards.

A metering chamber (7) is secured by appropriate means on the valve body (9), preferably at the lower section. The metering chamber is essentially constituted by a cover (71) and a bottom (72) within which slides a piston (73). This piston is subjected to the pressure of a spring (74) (of which only the end coils are shown) which, in the absence of other effort, tends to push it back against the cover (71).

The cover (71) of the metering chamber is essentially constituted by a radial wall (711) provided with a central opening (712) and two cylindrical walls (713, 714). The first cylindrical wall (713) extends the radial wall (711) downwardly. The second cylindrical wall (714), concentric with the first, extends upwardly around the central opening (712) of the radial wall (711). In the mounted state, the upper end of the second cylindrical wall (714) comes to bear against the lower face of the funnel-shaped portion (981) of the valve body, preferably with interposition of an annular ring (717) or any other suitable sealing means. A third cylindrical wall (715), concentric to the first two and surrounding the second, is provided for receiving the fixing means of the chamber (7) on the valve, preferably on the lower end of the valve body. In the example shown here, the fixing means are constituted by, on the one hand, two radial tenons in the shape of a circular arc placed on the outer face of the valve body (9), at its lower end, and two radial shoulders (718) directed toward the center and placed at the upper end of the inner face of the third cylindrical wall (715). In the assembled state, the two tenons of the valve body come to fit behind the two shoulders (718) of the third radial wall of the cover of the metering chamber. The seal is reinforced by the presence of the annular ring (717).

The bottom (72) of the metering chamber is constituted by a cylindrical wall (721) closed at the bottom by a radial wall (723). The inner diameter of the cylindrical wall (721) of the bottom (72) corresponds substantially to the outer diameter of the first cylindrical wall (713) of the cover (71). These two elements of the metering chamber can be connected with each other by any suitable means. In the example shown here, they are connected by means of four tenons (723) having the shape of an arc of a circle and distributed uniformly over the periphery of the cylindrical wall (721) of the bottom (72) and a same number of shoulders (716) provided in the first cylindrical wall (713) of the cover (71) and behind which the tenons (723) come to fit. Of course, as a possible alternative, it is the radial wall of the metering chamber that is separated from the rest of the metering chamber.

The piston (73) is essentially constituted by a full radial wall (731) (thus, without a passage opening, contrary to the valve of EP 1 099 647 A1), fixed on a cylindrical ring (732), the spring (74) penetrating into this cylindrical ring to bear on the lower face of the radial wall, or in the case shown here, on radial ribs (733) which are shorter than the cylindrical ring (732) and extend from the radial wall. A shoulder (734) formed on the outer face of the cylindrical ring (732) provides sealing between the piston (73) and the inner face of the cylindrical wall (721) of the bottom (72) of the metering chamber. The air contained inside the bottom (72) below the piston (73) is compressed when the chamber fills up.

The valve seal (5 a), of annular shape, is placed in the bottom of the dome, between the latter and the top face of the valve body.

The chamber seal (5 b) is placed inside the axial channel (95) of the valve body and it bears on the upper face of the first set of ribs (96). It is held in this position by the spacer (3). The chamber seal (5 b) has an annular shape. Its outer diameter corresponds to the inner diameter of the axial channel (95) above the first set of ribs (96). Its inner diameter corresponds to the outer diameter of the stem (4) at the first radial holes (45) and second radial holes (443). On its inner face, the chamber seal (5 b) has two parallel radial grooves (51 b, 52 b) located one above the other. The height of the lower groove (51 b) is greater than or equal to the axial distance separating the first radial holes (45) from the second radial holes (443) of the stem. In practice, it would be possible to dispense with the second radial groove (52 b), which plays no role. Its presence is justified only for reasons of simplification of the valve assembly: since the part is symmetrical about the radial center plane, it can be mounted one way or another in the valve body.

In the mounted state of the valve, there are, from bottom to top, the metering chamber (7) fixed on the lower section of the valve body (9). The stem (4) is located within the valve body (9), pushed back into the upper position by a spring (8) which is supported on one side on the shoulder (441) of the stem (4) and on the other on the upper face of the collar (98). The chamber seal (5 b) is blocked within the axial channel (95) between the top of the ribs of the first set (96) and the spacer (3) which is itself placed in the top part of the axial channel (95). Finally, the upper ring (91) of the valve body is secured to the cup (2), for example, by crimping with interposition of the valve seal (5 a) which surrounds the upper section of the stem (4). This seal ensure in particular sealing between the area located below it and that located above it.

To allow the product contained in the pouch (11) or the vial to enter the metering chamber, and then exit it, an inlet passage and an outlet passage are provided, inlet closure means and outlet closure means being respectively provided in the input path and the output path for closing these passages when necessary. When the respective closure means are open, the inlet passage contacts the inside of the pouch, or the inside of the vial if there is no pouch, and the metering chamber, while the outlet passage contacts the inside of the measuring chamber and the upper central channel (42) of the stem.

The inlet passage is constituted by the inlet orifices (99) made in the valve body, the orifice formed by the funnel-shaped portion (981) of the collar (98) of the valve body and the second cylindrical wall (714), then the orifice (712) of the cover (71) of the metering chamber. The inlet passage is clearly visible for example in FIG. 3 b, where it is indicated by an arrow. The closure means of this inlet passage are constituted by the tenon-shaped lower end of the second cylindrical wall (44) of the stem which, when the stem (4) is sufficiently lowered, comes to sealingly close the opening of the funnel-shaped portion (981) of the valve body and the annular ring (717). The closure of the inlet passage by the closure means input is clearly visible in FIGS. 4 b and 5 b.

The outlet passage is constituted by the orifice formed by the orifice (712) of the cover (71) of the metering chamber, the second cylindrical wall (714), the funnel-shaped portion (981) of the collar (98) of the valve body, the lower central channel (442) of the stem, the second set of radial holes (443), the first annular groove (51 b) of the chamber seal (5 b), the first set of radial holes (45) and the upper central channel (42). The outlet passage is clearly visible in FIG. 4 b where it is marked by an arrow. The closure means of the outlet passage are constituted by the inner face of the cylindrical wall of the chamber seal (5 b) which, as soon as the two sets of radial holes (45, 443) are no longer aligned with the first annular groove (51 b), constitutes a tight barrier between these two sets of holes, thereby closing the outlet passage. The closure of the outlet passage is clearly visible in FIGS. 3 b and 5 b.

When the valve is in the closed position, the radial holes (48) of the third cylindrical wall (46) of the stem are located above the valve seal (5 a), that is to say outside the valve. The radial holes (45) located at the bottom of the upper central channel (42) are located facing the upper groove (52 b) of the chamber seal (5 b) (or against the wall of the chamber seal which closes it if there is no second annular groove), while the second radial holes (443) are located facing the lower groove (51 b). Thus, the two sets of radial holes are isolated from each other and there is no communication between the lower central channel (442) and the upper central channel (42) of the stem (4). The tenon (44) of the stem penetrates into the orifice of the collar (98) but without coming into contact with the bottom of the funnel-shaped portion (981) and with the annular ring (717). The passage between the inside of the pouch (11) and the metering chamber is thus free. This passage proceeds through the radial holes (99), called inlet orifices, then the space located between the funnel-shaped portion (981) of the collar (98) and the lower end of the tenon (44), and finally the central orifice (712) of the cover of the metering chamber.

In this position the product placed within the pouch and compressed, for example to about 8 bar, by the gas located outside of it, penetrates through the orifices (99) into the axial channel (95), passes through the funnel-shaped portion (981) while going around the end of the tenon (44), and goes through the central orifice (712) of the cover (71) of the metering chamber by pushing the piston (73) against the action of spring (74). On the side of the valve body, the product goes up the lower axial channel (442) of the stem and fills the lower section of the valve body. However, it is blocked in the valve body by the chamber seal (5 b) and at the stem inside the bottom groove (51 b) of the chamber seal. The product cannot get out of the valve, but the metering chamber is filled.

When the valve is actuated, that is to say a pressure is exerted on the top portion of the stem, the latter moves downwards. To empty the metering chamber, the stem is designed to be lowered into an intermediate position between the high or closure position, and the low or short-circuit position.

In this intermediate position, the stem is lowered so that the radial holes (48) of the third cylindrical wall of the stem are again located above the valve seal (5 a). The radial holes (45) located in the lower portion of the upper central channel (42) of the stem, like the radial holes (443) located in the upper portion of the lower central channel (442), are situated facing the lower annular groove (51 b): they are thus in communication with each other. The lower end of the tenon (44) now enters the funnel-shaped portion (981) of the collar and thus sealingly closes the central orifice of the collar.

In this position, the product can no longer go from the pouch (or vial) into the metering chamber since the inlet passage between the inlet radial holes (99) and the metering chamber is closed by the sealed closure of the central hole of the collar by the tenon (44). On the contrary, the metering chamber being in contact with the outside, the pressure drops and the spring (74) pushes the piston (73) back to the upper portion of the metering chamber. The product is thus expelled. It passes first through the outlet opening (712) and the channel formed in the second cylindrical wall (714) of the cover (71), goes up in the lower channel (442) of the tenon (44), passes through the holes (443) of the tenon, circulates in the lower groove (51 b) of the chamber seal (5 b), passes through the holes (45) located in the lower portion of the upper central channel (42) of the stem, goes up the latter and arrives outside of the valve. Only the amount of product placed in the metering chamber can be expelled this way. At most, during the first use, the amount of material needed to fill the dead space formed by the path located inside the lower central channel (442) and the upper central channel (42) is missing. During subsequent uses, since this dead volume is already filled with product, the expelled volume corresponds exactly to the volume of the metering chamber (7).

When the pressure on the valve is released, the spring (8) pushes the stem (4) upwardly, the latter goes back to its initial position and the metering chamber fills up again.

It should be noted that regardless of the position of the stem, the product contained in the pouch can enter the side channels (931) of the fins (93) of the valve body and go through their orifices (94) to penetrate into the space located between the valve seal (5 a) and the chamber seal (5 b). However, this space is sealingly closed and the product contained therein cannot escape.

In some cases, it may be useful to bypass the metering chamber (7), for example to take a much larger dose of product. In this case, it is possible to exert an even greater pressure on the top face of the stem to force it to descend into the lowermost end position, beyond the intermediate position mentioned above. In this case, the radial holes (48) of the third cylindrical wall (46) of the stem pass below the valve seal (5 a), so they are in contact with the inside of the valve body. The radial holes (45) are facing the lower groove (51 b) of the chamber seal, while the radial holes (443) are located in the vicinity of the first and second set of ribs (96, 97). Thus, the upper central channel (42) and the lower central channel (442) are again isolated from each other. The tenon (44) penetrates even more into the funnel-shaped portion of the collar (98), maintaining the sealed closure of the central hole of the collar.

In this extreme position, the inlet and outlet passages are closed and the metering chamber is not only isolated from the pouch (11), but it is also isolated from the outside: it can neither be filled nor emptied. On the contrary, the product contained in the pouch (or vial) escapes through the valve via the side channels of the fins. It is pressed into the side channels (931) of the fins (93), passes through the orifices (94) that contact the top of the channels (931) and the inside of the upper ring (91), enters into the ring, passes between the ribs (31) of the spacer (3), passes through the holes (48) made in the third cylindrical wall (46) of the stem and leaves through the annular channel (47).

It should be noted that in the lowermost end position short-circuiting the metering chamber, it is also possible to fill the pocket during manufacture of the pressurized vial.

If the short-circuit position is not necessary, it is possible to dispense with the third cylindrical wall (46) of the stem and the side channels (931) of the valve body, even if the fins can be retained to facilitate welding of the pouch (11). The stem then moves only between the high closure position and the intermediate opening position, which then becomes the second end position.

The pouch is not essential either. It is possible to remove the product directly from the vial. As such, the valve can be used upside down (valve placed below the vial).

However, if it must be used in the normal position (valve above the vial), a plunger tube connected to the radial openings (99) of the lower section of the valve body and the side channels (931) of the fins must be provided.

In the embodiment shown here, the radial holes (45, 443, 48, 99) are provided in pairs. Of course, it would be possible to have only one each time, or on the contrary, more than two.

The metering valve of the invention, particularly associated with a pouch (11), can be used in any position. The presence of the spring (74) constraining the piston (73) ensures a fast and full exit of the product out of the metering chamber. Since the metering chamber is filled from the top, via the path that the product uses to exit, it is not at risk of being emptied between uses, even when one dispenses with using a pouch.

LIST OF REFERENCES

-   1 Metering valve     -   11 Soft pouch -   2 Cup     -   21 External ring     -   22 Dome -   3 Spacer     -   31 Radial ribs oriented outwardly -   4 Stem     -   41 First cylindrical wall     -   42 Upper central channel     -   43 Barrier     -   44 Second cylindrical wall/tenon         -   441 Circular shoulder         -   442 Lower central channel         -   443 Second set of radial holes     -   45 First set of radial holes     -   46 Third cylindrical wall     -   47 Annular channel     -   48 Third set of radial holes     -   49 a First stop     -   49 b Second stop -   5 a) Valve seal     -   b) Chamber seal     -   51 b Lower annular groove     -   52 b Upper annular groove -   7 Metering chamber     -   71 Cover         -   711 Radial wall         -   712 Central orifice         -   713 First cylindrical wall         -   714 Second cylindrical wall         -   715 Third cylindrical wall         -   716 Shoulder for fixing the bottom         -   717 Annular ring         -   718 Shoulder for fixing on the valve body     -   72 Bottom         -   721 Cylindrical wall         -   722 Radial wall         -   723 Tenons     -   73 Piston         -   731 Radial wall         -   732 Cylindrical ring         -   733 Radial ribs         -   734 Shoulder     -   74 Piston spring -   8 Stem spring -   9 Valve body     -   91 Upper ring     -   92 Main portion     -   93 Fins         -   931 Side channels     -   94 Holes     -   95 Axial channel     -   96 First set of ribs     -   97 Second set of ribs     -   98 Collar         -   981 Funnel-shaped portion     -   99 Radial holes 

1. Metering valve for a pressurized vial, comprising: a valve body, a valve element slidable in the valve body, a metering chamber, wherein the metering chamber is fixed by its upper end to the portion of the valve body located, in the mounted state, inside the vial, and means for moving the valve element between a closed position in which, in the mounted state on a vial, the metering chamber is in contact with the inside of the vial and isolated from the outside of the vial, and an open position in which, in the mounted state, the metering chamber is isolated from the inside of the vial and in contact with the outside of the vial, an inlet passage contacting the inside of the vial and the metering chamber and an outlet passage contacting the metering chamber and the outside of the valve, inlet closure means for closing the inlet passage when the valve element is in the open position and outlet closure means for closing the outlet passage when the valve element is in the closed position, and wherein the valve element can be moved beyond the open position into a third position, called short-circuit position, a third passage, called short-circuit passage, being provided to contact the inside of the vial and the outside of the valve, short-circuit closure means being provided to close the short-circuit passage when the valve element is in the closed position or the open position.
 2. Metering valve according to claim 1, wherein the short-circuit passage contacts the inside of the vial and the outside of the valve without passing through the metering chamber.
 3. Metering valve according to claim 1, wherein the inlet closure means and/or the outlet closure means are in the closed position when the valve element is in the short-circuit position if the short-circuit passage does not pass through at least a portion of the inlet passage and/or of the outlet passage.
 4. Metering valve according to claim 1, wherein the inlet closure means and the outlet closure means are independent from one another.
 5. Metering valve according to claim 1, wherein the inlet passage is constituted by at least one hole provided in the wall of the valve body, in a zone in contact with the inside of the vial or of the pouch, an orifice provided in a wall located within the valve body and an orifice provided in the metering chamber, and the inlet closure means are constituted by the lower end of the valve element having the shape of a cylindrical tenon and whose radial cross-section corresponds to the internal dimensions of the orifice in the wall so that when the tenon enters into this orifice, it closes it sealingly.
 6. Metering valve according to claim 5, wherein sealing means are placed below the orifice provided in the wall.
 7. Metering valve according to claim 1, wherein the outlet passage is constituted by an orifice provided in the metering chamber, an orifice provided in a wall located within the valve body, a lower central channel and an upper central channel provided in the valve element and separated from each other by a barrier, at least one orifice being provided in the wall of the valve element and contacting the inside of the upper central channel and the outside of the valve element and at least one orifice being provided in the wall of the valve element and contacting the inside of the lower central channel and the outside of the valve element, a contacting passage being provided for contacting the orifice or orifices of the lower central channel with the orifice or orifices of the upper central channel, and the outlet closure means are constituted by a chamber seal constituted by an annular wall within which the valve element is slidable, the inner face of the chamber seal having at least one annular groove whose height is at least equal to the vertical distance between the orifice or orifices provided in the upper central channel and the orifice or orifices provided in the lower central channel, the orifice or orifices of the upper central channel and/or the orifice or orifices of the lower central channel being closed by the inner face of the annular wall when the valve is in the closed position, thereby closing the outlet passage, and the orifice or orifices of the upper central channel and the orifice or orifices of the lower central channel opening into the annular groove when the valve is in the open position, thus freeing the outlet passage.
 8. Metering valve according to claim 1, wherein the metering chamber comprises a cylinder whose end opposite to the valve body, called lower end, is closed by a radial wall, called lower radial wall, and the end oriented toward the valve body, called upper end, is closed by a radial wall, called upper radial wall, a piston being slidable within the cylinder between these two radial walls thereby defining a metering volume.
 9. Metering valve according to claim 8, wherein the upper radial wall of the metering chamber is provided with an opening, the piston being slidable between the two radial walls of the cylinder, a spring being provided between the lower radial wall of the metering chamber and the piston to push the latter, in the absence of other constraints, against the upper radial wall provided with the opening.
 10. Metering valve according to claim 8, wherein the cylinder forming the metering chamber, on the one hand, and its upper radial wall and/or its lower radial wall, on the other hand, constitute separate parts that can be assembled or separated from one another, means being provided for fixing said wall on the cylinder.
 11. Metering valve according to claim 1, wherein a flexible pouch is welded to the valve body so as to enclose the metering chamber and the beginning of the inlet, outlet, and optionally short-circuit paths.
 12. Metering valve according to claim 1, wherein the valve element is constituted by a first cylindrical wall, called upper cylindrical wall, forming a first axial channel, called upper axial channel, and a second cylindrical wall forming a second axial channel, the two axial channels being isolated from each other by a barrier, the upper channel being open at its upper end by an axial opening and on the side of the barrier by at least one radial opening that opens onto the outer face of the valve element, the lower channel being open at its lower end by an axial opening and on the side of the barrier by at least one radial opening that opens onto the outer face of the valve element.
 13. Metering valve according to claim 12, wherein the valve element is provided with a third cylindrical wall at least partially surrounding the first cylindrical wall and concentric thereto so as to form an annular channel, said annular channel being isolated from the other two and provided with an axial opening at its end called upper end and at least one radial hole contacting the inside of the annular channel and the outside of the valve element, the valve body and the valve element are dimensioned so that the valve element can be moved beyond the open position into a position called short-circuit position, and the valve body is provided with a valve seal placed opposite to the metering chamber and positioned such that in the mounted state of the valve, the radial hole or holes of the annular channel are, in the closed position of the valve, located outside of the vial, in the open position of the valve, the radial hole or holes of the annular channel are located facing the valve seal and are closed by the latter, or outside the vial, and in the short-circuit position of the valve, the radial hole or holes of the annular channel are located on the side of the valve seal opposite to the outside.
 14. Metering valve according to claim 12, wherein the valve body is provided with a chamber seal disposed within the valve body so that in the closed position of the valve, the radial hole or holes of the upper channel of the valve element are located in the vicinity of the chamber seal and are closed by the latter, the annular stop coming to bear sealingly against this chamber seal.
 15. Metering valve according to claim 1, wherein at least one side channel is provided on the outer face of the valve body, said side channel being provided with a first opening that opens, in the mounted state, into the inside of the vial or pouch, and a second opening that opens into the inside of the valve body between the valve seal and the chamber seal.
 16. Metering valve according to claim 5, wherein the wall has a shape of a collar ending in a funnel shape oriented toward the metering chamber.
 17. Metering valve according to claim 6, wherein the sealing means comprise an annular ring.
 18. Metering valve according to claim 12, wherein the valve element is provided with at least one annular stop on its circumference to limit its movement within the valve body toward the outside or the inside.
 19. Metering valve according to claim 2, wherein the inlet closure means and/or the outlet closure means are in the closed position when the valve element is in the short-circuit position if the short-circuit passage does not pass through at least a portion of the inlet passage and/or of the outlet passage.
 20. Metering valve according to claim 2, wherein the inlet closure means and the outlet closure means are independent from one another. 